Improvement in machines for grinding lathe-centers



NL R'. L'EMMAN. Machine for Grinding Lathe-Centers.

510.160.921. Patented Marchfl6,1875.

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THE GRAPHIC C0.PHOT0.-LITH.39 &4T PARK PLACE,N.Y.

UNITED STATES .A TENT GEEIGE.

MARTIN R. LEMMAN, OF HAMILTON, OHIO.

IMPROVEMENT IN MACHINES FOR GRINDING LATHE-CEN'IERS.

Specification forming part oi Letters Patent No. l 60,921, dated March16, 1875; application filed April 24, 1874.

To all whom it may concern:

Be it known that I, MARTIN R. LEMMAN, of Hamilton, Butler county, Stateof Ohio, have invented a certain new and useful Improvement in Machinesfor Grinding the Centers of Lathes, of which the following is aspecification:

My invention relates to devices adapted to sharpen up accurately thecenter of a lathe while the same is revolving in the head-block spindle,and without its having been4 previously annealed; and my inventionconsists of an attachment adapted to be held in the tool-post of thelathe, and operated automatically by frictional contact with a detachable ring, which forms a part of my device, and is secured to theface-plate of the lathe, the operation being such that the frictionalcontact referred to sets in rapid motion an emerywheel joiirnaled in theattachment, and so located that its periphery acts upon vthe conicalcenter while the latter is revolving.

Figure l is a perspective view of an attach ment embodying my invention,and secured to a lathe. Fig. 2 is a plan of the same. Fig. 3 is a planof the attachment removed from the lathe. Fig. et is a sectional View ofthe spindle of the emery-wheel.

A is a frame, preferably of cast-iron, with a shank, a, formed upon it,to be secured within the ordinary tool-post of a lathe. The frame A hasalso formed upon it bearings O O for the support of the emery-wheelspin-l dle, and has adjustably secured to it a journal-bearing, D, forthe driving-spindle of the emery-wheel. E is the driving-spindle of theapparatus. It has a hub secured to it, which carries a series of leatherdisks, composing, in all, a conical frictional driving-pulley, F. At theother end of this shaft a large pulley, G, is secured, adapted to drivea small pulley, H, upon the emery-wheel spindle. In order that thefrictional contact between the pulleys Gr and H may be regulated, Iconnect the journal-bearing D to the frame A by a pivotscrew, I, and bya screw, J, in a curved slot in the' bearing, as shown in Fig. 3, sothat thebearing D may swing upon a pivot, and enable the face ofthepulley G tobe adj usted with relation to the face of the pulley H, andto be secured at any'point `of adjustment. The pulley H is secured to ahollow spindle, K, fitted between the bearings G C, and the emery-wheelL is secured to a hub, M, which slides loosely upon the same hollowspindle K. An interior spindle, k, fixed in the bearings O G, supportsthe wheelspindle K, through which it passes, and the emery-wheel hub hasa pin projecting from it into a groove in the hollowspindle K, so that,when the hollow spindle K revolves, the wheel L, although adapted toloosely slide upon the spindle K, must always revolve with it. A groove,m, is turned in the hub M for the attachment of the fork N of the slideO; The slide O is adapted to be moved backward and forward by thefingers of the operator, and in such movement the emery-wheel is carriedacross the face of the center I), which it is to grind. A loose rimmeddisk, R, is adapted to be secured to the ordinary face-plate S of thelathe, the periphery of which is turned off to match the periphery ofthe pulley F 5 and it will he seen that in the operation of thelathe-spindle this rim R is iliade to drive the einery-wheel, and as thelatter is brought in contact with the center of the lathe by theadjustment of the tool-post B, slide T, and carriage U, or either, thewheel is caused, in the backward and forward movement of the slide O, totrue up into perfect conical and concentric shape the center P. The hubof pulley F is secured to the spindle E by a set-screw, j', and isadjustable upon the spindle E to adapt the attachment for adjustment tolong and short centers.

The use of ring R makes this machine capable of universal application, agiven machine of very limited dimensions being adapted for truiiig upcenters of the largest lathe as well as the smallest, for it depends onitself' only for its action, and not upon the pulleys of the lathe, asheretofore.

I claim- 1. The detachable driving-ring R, in coinbination with acenter-grinding attachment such as described, substantially as and forthe purpose specified.

2. In combination with wheel L, spindle K,-

wheels H Gr F, spindle E, and frame A a, the pivoted adjustable bearingD I J, operating substantially as and for the purpose specified. Intestimony of which invention I hereunto set my hand.

MARTIN It. LEMMAN. Witnesses:

R. M. HUNTER, FRANK MILLWARD.

